In LTE wireless communication systems, vehicle-to-everything (V2X) generally utilizes the Sidelink interface, alternatively referred to as PC5, to enable V2X communications, including V2V (vehicle-to-vehicle) communications, V21 (vehicle-to-infrastructure) communications, V2P (vehicle-to-pedestrian) communications and V2N (vehicle-to-network) communications. The PC5 interface is built based on a mesh architecture of peer-to-peer device communication. LTE V2X also supports Uu interface (the radio interface between the mobile device and the radio access network) enhancement to assist the PC5 communications.
Existing (e.g., PC5-based) interfaces assume a mesh architecture in which every node is a peer to each other. This approach does not rely on any network infrastructure. However, spectrum efficiency cannot be very high because of the peer-to-peer structure. Another drawback of this mesh architecture is that it is not compatible with infrastructure-based cellular networks that utilize a hierarchical architecture. As a result, a separate spectrum needs to be obtained to deploy a V2X service based on a peer-to-peer mesh network architecture, which is very costly.